Image reading device and method

Abstract

The present invention has the objective of providing an image reading device capable of normally excellent reading of document images without influence from a soiled or damaged glass document platen, and eliminates the influence of a soiled or damaged glass surface of a document platen by normally reading document images using a new glass surface which is neither soiled not damaged by moving the document platen via a platen moving lever.

What is claimed is: 
     
       1. An image reading device for optically reading images of original documents, said image reading device comprising: a document platen;   a transport means for transporting a document in a predetermined direction onto said document platen;   a reading means for optically reading the image of the document transported by said transporting means through said document platen;   a measuring means for measuring the optical characteristics of said document platen to provide measurement data; and   a moving means for moving a relative position of said reading means and said document platen in accordance with the measurement data of said measuring means.   
     
     
       2. The image reading device as claimed in claim 1, wherein the moving means moves said document platen. 
     
     
       3. The image reading device as claimed in claim 1, wherein the moving means moves said reading means. 
     
     
       4. The image reading device as claimed in claim 1, wherein said reading means includes a lamp, a mirror and a CCD. 
     
     
       5. The image reading device as claimed in claim 4, wherein the moving means moves said lamp and said mirror. 
     
     
       6. The image reading device as claimed in claim 4, wherein the moving means moves said CCD. 
     
     
       7. The image reading device as claimed in claim 1, further comprising, a comparison means for comparing measurement data with predetermined reference data   wherein said moving means moves the relative positions of the document platen and reading means in accordance with the comparison result of the comparison means.   
     
     
       8. An image reading device for optically reading the image of original documents, said image reading device comprising: a document platen;   a transport means for transporting a document in a predetermined direction onto said document platen;   a reading means for optically reading the image of the document transported by said transporting means through said document platen and for measuring the optical characteristics of said document platen to provide measurement data;   a moving means for moving the relative position of said reading means and said document platen in accordance with the measurement data of said reading means.   
     
     
       9. The image reading device as claimed in claim 8, wherein the moving means moves said document platen. 
     
     
       10. The image reading device as claimed in claim 8, wherein the moving means moves said reading means. 
     
     
       11. An image reading device as claimed in claim 8, wherein said reading means includes a lamp, a mirror and a CCD. 
     
     
       12. The image reading device as claimed in claim 11, wherein the moving means moves said lamp and said mirror. 
     
     
       13. The image reading device as claimed in claim 11, wherein the moving means moves said CCD. 
     
     
       14. The image reading device as claimed in claim 8, further comprising, a comparison means for comparing measurement data with predetermined reference data   wherein said moving means moves the relative positions of the document platen and reading means in accordance with the comparison result of the comparison means.   
     
     
       15. An image reading method used in an image reader which reads a document image projected on an image sensor by an optical element, said image reading method comprising steps of detecting the soil of an optical element by said image sensor,   locating the soiled portion of the optical element out of the optical path for reading when said image sensor detect the soiled portion of said optical element, and   reading a document by said image sensor through said optical path where unsoiled portions of the optical elements are located.   
     
     
       16. An image reading method used in an image reader which reads a document image projected on an image sensor by an optical element, said image reading method comprising steps of detecting the soil of a optical element,   moving the optical element to locate the soiled portion of the optical element out of an optical path, and   reading a document by said image sensor through said optical path where unsoiled portions of the optical elements are located.   
     
     
       17. An image reading device for optically reading images of original documents, said image reading device comprising: a document platen;   a transport means for transporting a document in a predetermined direction onto said document platen;   an image reading means for optically reading the image of the document transported by said transporting means through said document platen;   a scanning means for scanning platen for optically reading the image of the document on said document platen by said image reading means;   a measuring means for measuring the optical characteristics of said document platen to provide measurement data; and   a moving means for moving the relative position of said reading means and said document platen in accordance with the measurement data of said measuring means.   
     
     
       18. The image reading device as claimed in claim 17, wherein the moving means moves said document platen. 
     
     
       19. The image reading device as claimed in claim 17, wherein the moving means moves said reading means. 
     
     
       20. The image reading device as claimed in claim 17, wherein said reading means includes a lamp, a mirror and a CCD. 
     
     
       21. The image reading device as claimed in claim 20, wherein the moving means moves said lamp and said mirror. 
     
     
       22. The image reading device as claimed in claim 20, wherein the moving means moves said CCD. 
     
     
       23. The image reading device as claimed in claim 17, further comprising, a comparison means for comparing measurement data with predetermined reference data   wherein said moving means moves the relative positions of the document platen and reading means in accordance with the comparison result of the comparison means.